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I wasn't trying to convince people to use the existing DNS infrastructure to propogate channel info, I was trying to convince people to adopt it's distributed heirarchy of authority for data management. I guess better examples would be X.500 or LDAP.<BR>
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I wanted to explore more the idea that data owners could put up program listing data on their local "server", and finding it would be easy and fast because the naming convention for owners would follow the DNS model, or something similar. This model also allows for "secondary" repositories that are knowable by the inquirer, and are authoritative because they get frequent full data dumps and differential data dumps from the "primary" source. The "name" of the station/server/service bounds the data. A server could be authoritative for more than one domain (ie. station). Perhaps the station names could be delegated by the cable/feed company names (Rogers-Toronto, Star Choice-Chicago, DirectTV-LosAngeles).<BR>
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Listings information at each station could be stored not as large chunks of aggregate data, but discrete chunks of smaller data elements, such as individual episode descriptions, with their time and date information, listing expiry, the level of confidence that this program will actually play at the advertized time, and other properties that the stations want to share about a particular TV episode. Queries could ask for specific information, or a complete dump of a station lineup, or something in between, and the limits of the data dump could be configured by each station. Perhaps a metadata query to get the properties of the data store (format, data dump limits, types or boundaries of the sets of aggregate data available) would precede a larger data request.<BR>
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I know Jay is flogging NNTP, but I just don't see how you get accurate listings, a complete lineup, JIT listing changes, etc. Would the proposed solution put an NNTP server at every station, or would they use existing commercial NNTP servers to propogate changes? How do you ensure everyone with a public NNTP relay carries the appropriate news groups? How do we tell people what news servers to point to? Will NNTP server administrators freak over the increased load on the servers that contain MythTV Listings Newsgroups? Perhaps I simpy don't know enough about NNTP. (I suppose that's pretty obvious). But a query response type mechanism initiated on demand by the user to a known repository that's authoritative seems to me to be the solution which has the promise to meet the service level requirements of the MythTV community, and to scale beyond.<BR>
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Just some thoughts.<BR>
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ICMan<BR>
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On Tue, 2007-26-06 at 10:03 -0400, Jay R. Ashworth wrote:
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<FONT COLOR="#000000">On Tue, Jun 26, 2007 at 01:56:28PM +0100, Peter Bowyer wrote:</FONT>
<FONT COLOR="#000000">> > hits will be differential data), DNS rules the Internet. Literally. With</FONT>
<FONT COLOR="#000000">> > the properties of such a mechanism, why is it not being seriously considered</FONT>
<FONT COLOR="#000000">> > on this list?</FONT>
<FONT COLOR="#000000">> </FONT>
<FONT COLOR="#000000">> Because it was designed for lightweight, moderately static data. As</FONT>
<FONT COLOR="#000000">> soon as you start loading DNS up with big records and the UDP queries</FONT>
<FONT COLOR="#000000">> have to become TCP queries, the advantages of the mechanism fall away.</FONT>
<FONT COLOR="#000000">And additionally, because our being able to use DNS-as-it-is in the</FONT>
<FONT COLOR="#000000">Internet at large for our purposes requires that it live up to</FONT>
<FONT COLOR="#000000">assumptions which are safe about DNS in the abstract, but not as it is</FONT>
<FONT COLOR="#000000">deployed.</FONT>
<FONT COLOR="#000000">Alternatively, we *can* make those same necessary assumptions about</FONT>
<FONT COLOR="#000000">NNTP as it is provided commercially. That's why I picked it. :-)</FONT>
<FONT COLOR="#000000">> Just because DNS is good at caching sub-128-byte name resolution</FONT>
<FONT COLOR="#000000">> queries, doesn't make it the right thing to use to move (relatively)</FONT>
<FONT COLOR="#000000">> heavy listings data around.</FONT>
<FONT COLOR="#000000">> </FONT>
<FONT COLOR="#000000">> Nail and hammer syndrome in evidence here.</FONT>
<FONT COLOR="#000000">Indeed. Plus, since you're leveraging the Internet DNS infrastructure</FONT>
<FONT COLOR="#000000">to do something it's not intended to do, you have little recourse when</FONT>
<FONT COLOR="#000000">it breaks.</FONT>
<FONT COLOR="#000000">And NANOG would murder you in your sleep. :-)</FONT>
<FONT COLOR="#000000">Cheers,</FONT>
<FONT COLOR="#000000">-- jra</FONT>
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